Meatal occluder for closing a lachrymal meatus

ABSTRACT

A meatal occluder for closing a lachrymal meatus of a human eye includes a substantially cylindrical body ( 10 ). It further includes at least one fin ( 13 ) adapted to take up a folded position, wherein the fin ( 13 ) is substantially folded into the cylindrical body ( 10 ), and an extended position wherein the fin ( 13 ) projects from the cylindrical body ( 10 ), the fin ( 13 ) being heat-deformable from the folded position to the extended position.

The present invention relates to a meatal occluder for closing alachrymal meatus.

This type of occluder is routinely used to occlude a lachrymal meatus ofa human eye, in the pathology known as “dry eye”, which corresponds toinsufficient production of lachrymal fluid by the lachrymal glands.

By inserting a meatal occluder into each lachrymal meatus, in the upperand lower part of the corner of each eye, the natural evacuation of thelachrymal fluid may be regulated to prevent dehydration of the eyes.

A device of the above kind is described in particular in the documentU.S. Pat. No. 6,234,175. The small device described in the abovedocument takes the form of a narrow cylinder having a diameter suitablefor insertion of the device into the canalicule extending the lachrymalmeatus.

The device is made of heat-sensitive acrylic so that it is softened anddeformed isovolumetrically when heated to a temperature above itsvitreous transition temperature.

When the device is placed in the lachrymal meatus, it responds to therise in temperature and expands in the widthwise direction to adapt tothe size and to the shape of the canalicule. However, it is stillpossible for the device to migrate either inside the canalicule, in thedirection of the nasal fossa, or to the exterior, since the cylindricalshape of the device is unable to guarantee that it is retained inposition.

An object of the present invention is to overcome the problems referredto above and to propose a meatal occluder that is retained in positioninside the lachrymal meatus in a particularly reliable manner.

The present invention is therefore directed to a meatal occluder forclosing a lachrymal meatus of a human eye that comprises a substantiallycylindrical body.

According to the invention, the meatal occluder comprises at least onefin adapted to take up a folded position, wherein the fin issubstantially folded into the cylindrical body, and an extendedposition, wherein the fin projects from the cylindrical body, said finbeing heat-deformable from said folded position to said extendedposition.

Thus the folded position of the fins preserves the cylindrical shape ofthe occluder, thereby facilitating its insertion into the lachrymalmeatus by the surgeon.

Inside the lachrymal meatus, the heat-deformable fin is extended becauseof the thermal effect generated by the human body. This projectingposition of the fin holds the occluder in position inside the lachrymalmeatus and thereby prevents its expulsion.

According to one preferred feature of the invention, the occluder ismade of a heat-expandable material so that the deformation of the finmay be readily obtained as soon as the occluder is placed in thecanalicule, because of the thermal effect of the human body.

According to one particularly practical feature of the invention, saidfin pivots between said folded position and said extended position aboutan axis perpendicular to a longitudinal plane of said meatal occluder.

The fins may therefore be extended in the manner of an umbrella, formingprojections around the cylindrical occluder adapted to come into contactwith the inside wall of the canalicule in which the occluder is placed.

According to another preferred feature of the invention, said fin issituated in the vicinity of a tapered end of said cylindrical body, theopposite end of said cylindrical body comprising a flange.

Thus the meatal occluder may be held in position at both ends, toprevent both its expulsion from the lachrymal meatus and its migrationdeeper into the canalicule.

According to one particularly advantageous feature of the invention,reinforcing the retention of the occluder in position, the occludercomprises a plurality of fins regularly distributed on the cylindricalbody of said occluder.

Other features and advantages of the invention will emerge further inthe following description.

In the appended drawings, which are provided by way of nonlimitingexample:

FIG. 1A is a bottom view of a meatal occluder conforming to a firstembodiment of the invention;

FIG. 1B is a view in longitudinal section of the FIG. 1A meataloccluder;

FIG. 2A is a bottom view of a meatal occluder conforming to a secondembodiment of the invention;

FIG. 2B is a view in longitudinal section of the FIG. 2A meataloccluder;

FIG. 3A is a bottom view of a meatal occluder conforming to a thirdembodiment of the invention;

FIG. 3B is a view in longitudinal section of the FIG. 3A meataloccluder;

FIG. 4A is a bottom view of a meatal occluder conforming to a fourthembodiment of the invention;

FIG. 4B is a view in longitudinal section of the FIG. 4A meataloccluder;

FIG. 5A is a bottom view of a meatal occluder conforming to a fifthembodiment of the invention;

FIG. 5B is a view in longitudinal section of the FIG. 5A meataloccluder; and

FIGS. 6 and 7 are diagrammatic views showing the positioning of themeatal occluder in the lachrymal meatus, respectively with the finsfolded and extended.

A first embodiment of a meatal occluder conforming to the invention isdescribed first with reference to FIGS. 1A and 1B.

In a manner that is known in the art, this meatal occluder is used toclose a lachrymal meatus of a human eye in order to limit the loss oflachrymal liquid.

The meatal occluder comprises a substantially cylindrical body 10 havinga flange 11 at a first end 10 a.

The longitudinal direction of the cylindrical body extends along an axisX.

The cylindrical body 10 is bored along its longitudinal direction X withthe result that it comprises a longitudinal orifice 12, also ofsubstantially cylindrical shape, that opens from the body 10 at itsfirst end 10 a, inside the flange 11.

The longitudinal orifice 12 stops short of a second end 10 b of thecylindrical body and therefore has a closed bottom 12 a inside thecylindrical body 10.

In a manner that is known in the art, this longitudinal orifice 12inside the meatal occluder is used to insert an occluder fitting deviceused to place the meatal occluder in the lachrymal meatus.

To facilitate the insertion of the meatal occluder into the lachrymalmeatus, the second end 10 b of the cylindrical body is tapered. Thistapered end 10 b of the occluder is the end that is inserted into thelachrymal meatus.

In this embodiment, the meatal occluder comprises two fins 13 regularlydistributed on the cylindrical body 10 of the occluder, i.e. disposedalong a diameter of the occluder.

As is clearly shown, each fin 13 is adapted to occupy a folded position,wherein the fin 13 is retracted inside the cylindrical body 10 (see theright-hand part of FIGS. 1A and 1B), and an extended position, whereinthe fin 13 projects from the cylindrical body 10 (see the left-hand partof FIGS. 1A and 1B).

In order to explain the invention, one of the fins is shown in theextended position and the other in the folded position; in reality, thefins 13 are either both folded or both extended, of course.

The fins 13 pivot between their folded position and their extendedposition about an axis perpendicular to a longitudinal plane of theoccluder, i.e. an axis perpendicular to the plane of FIG. 1B.

In their folded position, the fins 13 extend in a directionsubstantially parallel to the longitudinal direction X of thecylindrical body 10, so that the insertion of the tapered end 10 b ofthe occluder is not impeded by the presence of the fins.

Here, each fin 13 is situated in the vicinity of the second end 10 b ofthe cylindrical body 10, the free end 13 a of each fin 13 when in thefolded position extending in the direction of the first end 10 a of thecylindrical body.

In their extended position, the fins 13 extend substantially in atransverse plane of the cylindrical body 10 of the occluder.

A second embodiment of a meatal occluder conforming to the invention isdescribed next with reference to FIGS. 2A and 2B.

In these and all subsequent figures, elements common to the firstembodiment carry the same reference numbers and do not need to bedescribed in detail.

In this second embodiment, the occluder also comprises two fins 13adapted to pivot between a folded position and an extended positionaround an axis perpendicular to a longitudinal plane of the occluder,i.e. an axis perpendicular to the plane of FIG. 2B.

In this embodiment, the free end 13 a of each fin is tapered.

Unlike the first embodiment, in which the free end 13 a of each fin 13extends along the cylindrical body 10 beyond the bottom 12 a of thelongitudinal orifice 12, in this second embodiment the end 13 a of eachfin 13 terminates substantially at the level of the transverse planecoinciding with the bottom 12 a of the longitudinal orifice 12.

Furthermore, the second end 10 b of the cylindrical body 10 is nottapered, as such, but hemispherical.

A third embodiment of a meatal occluder conforming to the invention isdescribed next with reference to FIGS. 3A and 3B.

This occluder also has two fins 13 adapted to be extended by pivotingabout an axis perpendicular to the longitudinal plane of the occluder.

As in the second embodiment, the ends 13 a of each fin 13 are tapered.

Unlike the first and second embodiments, the free end 13 a of each fin13 terminates short of the bottom 12 a of the longitudinal orifice 12 ofthe occluder.

In each of the above embodiments, the cylindrical body 10 of theoccluder comprises a portion 10′ of reduced diameter inside which thefins 13 lie in their folded position.

A fourth embodiment of a meatal occluder conforming to the invention isdescribed next with reference to FIGS. 4A and 4B.

Unlike the first three embodiments, this occluder comprises three finsregularly distributed on the cylindrical body 10 of the occluder.

The fins 13 are therefore disposed at 120° to each other.

As previously, the fins are adapted to pivot about an axis perpendicularto the longitudinal plane of the occluder between a folded position,retracted inside a reduced diameter portion 10′ of the cylindrical body10, and an extended position.

In this extended position, each fin 13 lies in a plane transverse to thelongitudinal direction X of the occluder 10.

As previously, the cylindrical body 10 of the occluder has a flange at afirst end 10 a and a tapered second end 10 b.

In this embodiment with three fins 13, the free end 13 a of each finextends substantially as far as the transverse plane of the occludercorresponding to the bottom 12 a of the longitudinal orifice 12 providedinside the cylindrical body 10 for inserting an occluder fitting device.

Finally, a fifth embodiment of a meatal occluder conforming to theinvention is described with reference to FIGS. 5A and 5B.

This meatal occluder again comprises two fins 13.

Unlike the preceding embodiments, these fins 13 are adapted to pivotbetween their folded position and their extended position about an axisparallel to the longitudinal direction X of the cylindrical body 10 ofthe occluder.

The fins 13 therefore move in a common transverse plane of thecylindrical body 10 situated between the bottom 12 a of the longitudinalorifice of the occluder and the tapered end 10 b of the occluder.

In the folded position, the fins 13 are accommodated inside a reduceddiameter portion 10′ of the cylindrical body 10.

In all the foregoing embodiments, the meatal occluder may be made from aheat-expandable material so that the fins 13 are extended by the actionof heat.

Thus each fin 13 is heat-deformable from its folded position to itsextended position.

The materials from which the occluder may be made may be chosen fromdifferent types of polymers, homopolymers, cross-linked polymers,silicones, acrylic polymers, polyurethanes and hydrocarbonated polymers.

Of course, the occluder may equally be made from a combination of theforegoing polymers.

The above polymers are biologically inert, biocompatible, andnon-immunogenic.

These polymers may be grouped into two classes, distinguished by theirmelting point Tf of their vitreous transition temperature Tg.

Polymers having a vitreous transition temperature Tg from −10° C. to 30°C., and in any event less than or equal to 37° C., include in particularsilicones, acrylics, polyurethanes, hydrocarbonated polymers and theircopolymers.

These copolymers may be formulated with waxes such as octadecane oroligomers of polyethylene to increase their stiffness at temperaturesbelow the vitreous transition temperature of the material.

By way of nonlimiting example, a mixture of lauryl methacrylate in aproportion of 40% by weight and methyl methacrylate in a proportion of60% by weight yields a copolymer having a vitreous transitiontemperature of the order of 19° C.

Polymers having a melting point Tf less than or equal to 37° C. may beused instead. For example, acrylic polymers having a long side chainable to crystallize may be used in this application.

By way of nonlimiting example, a stearyl polymethacrylate having amelting point of the order of 34° C. may be used.

A finned occluder of the above kind may be injection molded at lowpressure.

A twin-shell multi-imprint mold is assembled in a sealed manner. Aftermixing the various monomers and other constituents, the composition maybe injected into the mold. The mold is then placed in atemperature-controlled oven for a period from 5 to 72 hours topolymerize the materials.

After polymerization, the mold is disassembled and the meatal occluderis removed from its imprint.

Molding stalks are generally cut off by hand and a visual inspection maybe carried out to eliminate occluders that do not satisfy predefinedquality criteria.

Depending on the type of polymers used, the occluder may be heated to atemperature above its vitreous transition temperature Tg or its meltingpoint Tf and the fins folded along the body of the occluder, into thereduced diameter portion 10′ of the cylindrical body 10, in order toreduce the overall size.

The occluder is then cooled by a jet of cooled air and placed on anoccluder fitting device by means of the longitudinal orifice 12.

A piece of non-deformable tube, for example a thick-walled siliconetube, is placed around the occluder, forming a sleeve to prevent thefins 13 extending before use, even if the recommended storagetemperature is temporarily exceeded.

Otherwise, exceeding the recommended storage temperature, and inparticular an increase in the temperature above 37° C., wouldinstantaneously cause the fins 13 to extend.

The occluder may then be placed in a blister pack and sterilized.

As shown clearly in FIGS. 6 and 7, the occluder may be inserted into thelachrymal meatus at room temperature with the fins 13 in the foldedposition.

Thus, during insertion, the occluder of the invention has asubstantially cylindrical shape, facilitating its insertion into thelachrymal meatus and then into the canalicule 14.

As soon as the meatal occluder is in position inside the canalicule 14,the heat-deformable fins 13 resume their extended position, because ofthe heating effect of the human body, coming into close contact with theinside wall of the canalicule.

The extended fins 13 therefore hold the occluder reliably in positioninside the canalicule.

Of course, numerous modifications may be made to the embodimentsdescribed hereinabove without departing from the scope of the invention.

1. A meatal occluder for closing a lachrymal meatus of a human eye,comprising a substantially cylindrical body (10) and characterized inthat it further comprises at least one fin (13) adapted to take up afolded position, wherein the fin (13) is substantially folded into thecylindrical body (10), and an extended position wherein the fin (13)projects from the cylindrical body (10), said fin (13) beingheat-deformable from said folded position to said extended position. 2.Meatal occluder according to claim 1, characterized in that it is madefrom a heat-expandable material.
 3. Meatal occluder according to claim1, characterized in that it is made from polymers chosen from a groupcomprising polymers, homopolymers, cross-linked polymers, silicones,acrylic polymers, polyurethanes, hydrocarbonated polymers and acombination of the above polymers.
 4. Meatal occluder according to claim2, characterized in that the heat-expandable material has a vitreoustransition temperature from −10° C. to 30° C.
 5. Meatal occluderaccording to claim 1 characterized in that said fin (13) pivots betweensaid folded position and said extended position about an axisperpendicular to a longitudinal plane of said meatal occluder.
 6. Meataloccluder according to claim 5, characterized in that said fin (13) whenin said folded position extends in a direction substantially parallel tothe longitudinal direction (X) of the cylindrical body (10).
 7. Meataloccluder according to claim 5, characterized in that said fin (13) issituated in the vicinity of one end (lob) of said cylindrical body (10),a free end (13 a) of said fin (13), when in the folded position,extending in the direction of the opposite end (10 a) of saidcylindrical body (10).
 8. Meatal occluder according to claim 1characterized in that said fin (13) pivots between said folded positionand said extended position about an axis parallel to the longitudinaldirection (X) of the cylindrical body (10).
 9. Meatal occluder accordingto claim 1, characterized in that said fin (13) is situated in thevicinity of a tapered end (10 b) of said cylindrical body (10), theopposite end (10 a) of said cylindrical body (10) comprising a flange(11).
 10. Meatal occluder according to claim 1, characterized in that itcomprises a plurality of fins (13) regularly distributed on thecylindrical body (10) of said occluder.